Conventionally, in the semiconductor industry and the like, generally used is a processing stage apparatus which comprises a movable table capable of precise movement in order to set and hold a workpiece in a position for precision processing or for an inspection, etc. in a manufacturing process of IC, LSI and the like.
In this case, in order to precisely move the movable table to an arbitrary position on an X-Y plane, generally used is a type of apparatus comprising a moving-body holding mechanism in a double structure, in which, first, the entire movable table is moved by an X-direction moving mechanism in the X direction and subsequently (or simultaneously) the entire movable table and the X-direction moving mechanism are moved by a Y-direction moving mechanism in the Y direction.
Further, most of the processing stage apparatus of this kind comprises a mechanical braking mechanism which drives at a relatively slow speed for controlling the movement of the movable table in the X direction and Y direction.
However, the conventional stage apparatus comprises: the moving-body holding mechanism in a double structure in which, as described above, the X-direction moving mechanism for movements in the X direction and the Y-direction moving mechanism for movements in the Y direction intersect with each other; and the in-contact moving section which especially requires the precision has a running-in structure. Therefore, it is time-consuming to perform processing and also requires a skill to perform precise adjustment at the time of assembling, thereby causing inconvenience. Thus, the productivity is deteriorated so that the price of the whole apparatus is increased in many cases.
Furthermore, for automating the system in connection with moving the table, it requires a large space for connecting the double-structures driving mechanism and mounting a positioning sensor and the like. Thus, the whole apparatus becomes large-scaled.
Moreover, in most of the conventional stage apparatuses, a return spring for returning to the original position is provided to the movable table. In this case, a slight reciprocal movement is likely to be generated in the movable table at a stop position due to the acceleration or deceleration of the driving force applied to the movable table at the time of stopping the movable table. Thus, a mechanical braking device utilizing friction is essential for making a stop at a prescribed position.
In the meantime, this type of mechanical friction braking is likely to generate small oscillation at the time of operation, so that the movement when making a stop becomes unstable when performing precision movement by micron unit. Also, the whole apparatus becomes large-scaled since the mechanical braking mechanism is provided, so that there always faces the shortcomings that the portability is bad and the maintenance characteristic is also deteriorated.
An object of the present invention is to provide a precision processing stage apparatus comprising a function of smoothly carrying out a precise moving of a precision processing movable table on the same plane in prescribed directions, which is capable of a dramatic improvement in assembling work, reduction of the size and weight of the whole apparatus and, further, of suppressing the reciprocal movement and small oscillation or the like at the time of stopping the movable table, thereby achieving fast and smooth precision movement of the movable table.